Not Applicable
1. Field of the Invention
This invention relates to an expandable reamer for use in surgery, particularly in orthopedic applications.
2. Description of the Related Art
U.S. Pat. No. 5,445,639 to Kuslich et al., describes an intervertebral reamer which is used to ream out the interior of a degenerated disc to clean the interbody space. U.S. Pat. Nos. 5,549,679 and 5,571,189 to Kuslich describes a device and method for stabilizing the spinal segment with an expandable, porous fabric implant for insertion into the interior of a reamed out disc which is packed with material to facilitate bony fusion.
U.S. Pat. No. 5,928,239 to Mirza discloses a reamer which has a shaft and a cutting tip attached through a free rotating hinge such that high speed rotation allows the tip to be deflected outwardly to form a cavity. U.S. Pat. No. 5,591,170 to Spievack et al discloses a powered bone saw which inserts its cutting blade through a bored intramedullary canal.
The reamer of U.S. Pat. No. 5,445,639 is better suited to make a cylindrical bore than a spherical bore as is needed for the methods and apparatus of U.S. Pat. Nos. 5,549,679 and 5,571,189, the disclosure of all of which are incorporated herein by reference. There exists, therefore, a need for an instrument which will simplify the surgeon""s task of forming a chamber within the interbody space.
The art described in this section is not intended to constitute an admission that any patent, publication or other information referred to herein is xe2x80x9cprior artxe2x80x9d with respect to this invention, unless specifically designated as such. In addition, this section should not be construed to mean that a search has been made or that no other pertinent information as defined in 37 C.F.R. xc2xa7 1.56(a) exists.
The invention provides a surgical tool is for forming hollow chambers within bone that are larger in diameter than the external opening into the chamber. The tool has a distal end with external dimensions sized to be passed through the patient""s anatomy to a point of entry into the bone. Retractable cutting blades are provided on the cutting end. The blades can be extended to cut a cavity greater than the diameter of the surgical tool.